1. Field of the invention
The present invention relates to a plug type connector, and more particularly to a plug type connector having a locking function of, when the connector is connected to a counter connector, coupling the connector to the counter connector.
In the plug type connector of the invention, in the case where a locking member is formed by a slender locking piece configured by a synthetic resin molded product, the level of the operation load which is required for flexurally deforming the locking piece can be increasingly or decreasingly adjusted. In the case where a locking member is made of a metal, the enclosure of the counter connector is not shaved by a prying force applied on the counter connector, and hence the stability of the locked state can be enhanced. In the invention, moreover, a measure for enabling such a plug type connector to be easily miniaturized is taken.
2. Description of the Prior Art
Japanese Patent Application Laying-Open No. 2001-176620, Japanese Utility Model Application Laying-Open No. 6-19284, and U.S. Pat. No. 6,071,141 disclose plug type connectors of this type. In the plug type connectors, a spring plate configured by a sheet metal is employed as a locking member for exerting a locking function.
In the case where a spring plate configured by a sheet metal is used as a locking member, however, the following situation may often occur because the spring plate itself has the property of being easily bent. When the tip end of the spring plate protrudes in front of an enclosure of the plug type connector, the exposed portion of the tip end of the spring plate accidentally interferes with any other article to be deformed.
In a plug type connector using a spring plate configured by a sheet metal, moreover, the following situation may often occur. When a prying force is applied during a work of connecting or disconnecting the plug type connector from a counter connector, the enclosure (housing, case) of the counter connector is shaved by an edge of the sheet metal spring plate. When such a situation repeatedly occurs as a result of frequent repetition of connection and disconnection, the position of an engaged portion between the sheet metal locking member and the counter connector is changed, thereby causing a problem in that the stability of the locked state is impaired.
In order to solve the problem, it is contemplated to use a slender locking piece configured as a synthetic resin molded product which has the property of being hardly bent relative to a sheet metal spring plate, as a locking member. In the case where a slender locking piece configured as a synthetic resin molded product which is hardly bent is used as a locking member, even when the tip end of the locking member protrudes in front of an enclosure of the plug type connector to be exposed therefrom, the exposed portion is hardly deformed. U.S. Pat. No. Des. 424,519 discloses an example in which a locking member is configured by a resin molded product.
When, in order to adjust the level of a load required for flexural deformation in such a slender locking piece made of a synthetic resin, a usual technique is employed in which the length of the locking piece is changed to use the principle of the lever that is exerted by the locking piece itself, the change of the length of the locking piece affects the whole size of the plug type connector. When the load required for flexural deformation (deformation load) is to be reduced, therefore, the locking piece must be prolonged, so that the overall size of the plug type connector is increased. In a connector in which a locking member is formed as a resin molded product, when the strength required for the locking member is to be ensured, the size of the locking member itself is increased. This causes the appearance of the plug type connector to be changed, and, particularly, the width of the plug type connector to be prolonged, thereby producing a problem in that miniaturization of a plug type connector is impaired.